In a large saucepan cook bacon over medium-high heat until crisp. Remove with slotted spoon, set aside. Drain all but 1 tablespoon drippings. Add butter and melt.

Add leeks, onion, carrots and garlic and cook for 5 minutes. Stir in flour. Gradually stir in chicken broth.

Add potatoes. Bring to a boil. Reduce heat, cook partially covered for 15 minutes or until potatoes are tender.

Place cheese in a large mixing bowl. Stir in about a quarter of the hot soup, mixing until smooth. Return cheese mixture to saucepan.

Gradually stir in heavy cream, salt and ground pepper. Continue to heat soup until almost boiling. Serve warm.